The Internet Corporation for Assigned Names and Numbers is a global multistakeholder group and nonprofit organization head-quartered in the United States responsible for coordinating the maintenance and procedures of several databases related to the namespaces and numerical spaces of the Internet, ensuring the Internet's stable and secure operation. ICANN performs the actual technical maintenance work of the Central Internet Address pools and DNS root zone registries pursuant to the Internet Assigned Numbers Authority (IANA) function contract. The contract regarding the IANA stewardship functions between ICANN and the National Telecommunications and Information Administration (NTIA) of the United States Department of Commerce ended on October 1, 2016, formally transitioning the functions to the global multistakeholder community.
A top-level domain (TLD) is one of the domains at the highest level in the hierarchical Domain Name System of the Internet after the root domain. The top-level domain names are installed in the root zone of the name space. For all domains in lower levels, it is the last part of the domain name, that is, the last non empty label of a fully qualified domain name. For example, in the domain name www.example.com, the top-level domain is .com. Responsibility for management of most top-level domains is delegated to specific organizations by the ICANN, an Internet multi-stakeholder community, which operates the Internet Assigned Numbers Authority (IANA), and is in charge of maintaining the DNS root zone.
In the Internet, a domain name is a string that identifies a realm of administrative autonomy, authority or control. Domain names are often used to identify services provided through the Internet, such as websites, email services and more. As of December 2023, 359.8 million domain names had been registered. Domain names are used in various networking contexts and for application-specific naming and addressing purposes. In general, a domain name identifies a network domain or an Internet Protocol (IP) resource, such as a personal computer used to access the Internet, or a server computer.
A domain name registry is a database of all domain names and the associated registrant information in the top level domains of the Domain Name System (DNS) of the Internet that enables third party entities to request administrative control of a domain name. Most registries operate on the top-level and second-level of the DNS.
.hk is the designated Internet country code top-level domain (ccTLD) for Hong Kong. It is administered by the Hong Kong Internet Registration Corporation (HKIRC), the only organization endorsed by the Hong Kong Government to undertake the administration of 'hk' domain names. Hong Kong Internet Registration Corporation (HKIRC) is a non-profit making, non-statutory, member-based corporation established in 2001.
The domain name .org is a generic top-level domain (gTLD) of the Domain Name System (DNS) used on the Internet. The name is truncated from 'organization'. It was one of the original domains established in 1985, and has been operated by the Public Interest Registry since 2003. The domain was originally "intended as the miscellaneous TLD for organizations that didn't fit anywhere else." It is commonly used by non-profit organizations, open-source projects, and communities, but is an open domain that can be used by anyone. The number of registered domains in .org has increased from fewer than one million in the 1990s, to ten million in 2012, and held steady between ten and eleven million since then.
The Internet uses the Domain Name System (DNS) to associate numeric computer IP addresses with human-readable names. The top level of the domain name hierarchy, the DNS root, contains the top-level domains that appear as the suffixes of all Internet domain names. The most widely used DNS root is administered by the Internet Corporation for Assigned Names and Numbers (ICANN). In addition, several organizations operate alternative DNS roots, often referred to as alt roots. These alternative domain name systems operate their own root name servers and commonly administer their own specific name spaces consisting of custom top-level domains.
An internationalized domain name (IDN) is an Internet domain name that contains at least one label displayed in software applications, in whole or in part, in non-Latin script or alphabet or in the Latin alphabet-based characters with diacritics or ligatures. These writing systems are encoded by computers in multibyte Unicode. Internationalized domain names are stored in the Domain Name System (DNS) as ASCII strings using Punycode transcription.
AlterNIC was an unofficial, controversial Internet domain name registry that relied on an alternative DNS root. The primary purpose of the project was to challenge the monopoly of InterNIC, the official governing body for generic top-level domains (gTLDs) until the creation of the ICANN in 1998. AlterNIC offered second level domain registration in its own TLDs at lower prices than InterNIC. However, these domain names could only be resolved by name servers that were specifically configured to use the AlterNIC root zone. The project is now defunct; the domain name alternic.net is parked and no longer associated with AlterNIC.
A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country, sovereign state, or dependent territory identified with a country code. All ASCII ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs.
.sa is the Latin alphabet Internet country code top-level domain (ccTLD) of Saudi Arabia. Domains of this type can be registered through SaudiNIC, a department of the Communications and Information Technology Commission. The Arabic alphabet ccTLD of Saudi Arabia is السعودية.
.il is the Internet country code top-level domain (ccTLD) of Israel, administered by the Israel Internet Association and managed by NIC - ISRAEL, which hosts the DNS root server and manages the Israeli Internet Exchange, that supports IPv4 and IPv6.
The Canadian Internet Registration Authority (CIRA) is the organization that manages the .ca country code top-level domain (ccTLD) for Canada. Its offices are located at 979 Bank Street in Ottawa, Ontario, Canada. CIRA sets the policies and agendas that support Canada's internet community and Canada's involvement in international internet governance. It is a member-driven organization with membership open to all that hold a .ca domain. As of March 2023, there were more than 3.3 million active .ca domains.
.um was the Internet country code top-level domain for the United States Minor Outlying Islands. It was administered by the United States Minor Outlying Islands Registry. Until late 2006 USMIR was housed at the University of Southern California Information Sciences Institute (USC-ISI), which was the original administrator of .us prior to NeuStar absorbing that role.
.so is the internet country code top-level domain (ccTLD) for Somalia. After a long absence, the .so domain was officially relaunched on November 1, 2010, by .SO Registry, which is regulated by the nation's Ministry of Posts and Telecommunications. It was launched through various accredited registrars around the world.
.mr is the Internet country code top-level domain (ccTLD) for Mauritania.
An internationalized country code top-level domain is a top-level domain in the Domain Name System (DNS) of the Internet. IDN ccTLDs are specially encoded domain names that are displayed in an end user application, such as a web browser, in their language-native script or alphabet, such as the Arabic alphabet, or a non-alphabetic writing system, such as Chinese characters. IDN ccTLDs are an application of the internationalized domain name system to top-level Internet domains assigned to countries, or independent geographic regions.
.vlaanderen is a generic top-level domain for Flanders, Belgium first introduced in 2014.
OpenNIC is a user-owned and -controlled top-level Network Information Center that offers a non-national alternative to traditional top-level domain (TLD) registries such as ICANN. As of January 2017, OpenNIC recognizes and peers all existing ICANN TLDs, for compatibility reasons. However, OpenNIC has not yet evaluated and does not hold a formal position on future ICANN TLDs.
South Sudan 
